Linear Technology LT1792 Datasheet

FEATURES

LT1792

Low Noise, Precision,

JFET Input Op Amp

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DESCRIPTIO

■

100% Tested Low Voltage Noise: 6nV/√Hz Max

■

A Grade 100% Temperature Tested

■

Voltage Gain: 1.2 Million Min

■

Offset Voltage Over Temp: 800µV Max

■

Gain-Bandwidth Product: 5.6MHz Typ

■

Guaranteed Specifications with ±5V Supplies

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APPLICATIO S

■

Photocurrent Amplifiers

■

Hydrophone Amplifiers

■

High Sensitivity Piezoelectric Accelerometers

■

Low Voltage and Current Noise Instrumentation
Amplifier Front Ends

■

Two and Three Op Amp Instrumentation Amplifiers

■

Active Filters

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TYPICAL APPLICATIO

The LT®1792 achieves a new standard of excellence in
noise performance for a JFET op amp. The 4.2nV/√Hz
voltage noise combined with low current noise and
picoampere bias currents make the LT1792 an ideal choice
for amplifying low level signals from high impedance
capacitive transducers.

The LT1792 is unconditionally stable for gains of 1 or more,
even with load capacitances up to 1000pF. Other key
features are 600µV VOS and a voltage gain of over 4 million.
Each individual amplifier is 100% tested for voltage noise,
slew rate and gain bandwidth.

The design of the LT1792 has been optimized to achieve
true precision performance with an industry standard
pinout in the SO-8 package. Specifications are also pro­vided for ±5V supplies.

, LTC and LT are registered trademarks of Linear Technology Corporation.

Low Noise Hydrophone Amplifier with DC Servo

2

3

–5V TO –15V

R8
100M

R7
1M

< 70°C

A

5V TO 15V

–

LT1792

+

R6

100k

7

6

4

C2

0.47µF

6

LT1097

R1*
100M

R2
200Ω

HYDRO-

PHONE

DC OUTPUT ≤ 2.5mV FOR T
OUTPUT VOLTAGE NOISE = 128nV/√Hz AT 1kHz (GAIN = 20)
C1 ≈ C

T

R3

3.9k

C1*

C

T

≈ 100pF TO 5000pF; R4C2 > R8CT; *OPTIONAL

1kHz Input Noise Voltage Distribution

VS = ±15V

40

= 25°C

T

A

OUTPUT

R4
1M

–

2

R5
1M

3

+

1792 TA01

30

20

PERCENT OF UNITS (%)

10

0

3.8 4.2

3.6

4.0

INPUT VOLTAGE NOISE (nV/√Hz)

270 OP AMPS TESTED

5.0

4.6 5.6

4.8

4.4

5.2

5.4

1792 TA02

1

LT1792

A

W

O

LUTEXI TIS

S

A

WUW

U

ARB

G

(Note 1)

Supply Voltage ..................................................... ±20V

Differential Input Voltage ...................................... ±40V

Input Voltage (Equal to Supply Voltage)............... ±20V

Output Short-Circuit Duration ........................ Indefinite

Operating Temperature Range............... –40°C to 85°C

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/

PACKAGE

VOS ADJ

–IN A
+IN A

–

V

JMAX

O

RDER I FOR ATIO

TOP VIEW

1
2

A

3
4

N8 PACKAGE
8-LEAD PDIP

= 140°C, θJA = 130°C/W

ORDER PART

NUMBER

NC

8

+

V

7

OUT

6

ADJ

V

5

OS

LT1792ACN8
LT1792CN8
LT1792AIN8
LT1792IN8

Specified Temperature Range

Commercial (Note 8) ......................... –40°C to 85°C

Industrial ........................................... –40°C to 85°C

Storage Temperature Range................ –65°C to 150°C

Lead Temperature (Soldering, 10 sec) ................ 300°C

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ORDER PART

NUMBER

LT1792ACS8
LT1792CS8
LT1792AIS8
LT1792IS8

S8 PART MARKING

1792A
1792

VOS ADJ

–IN A
+IN A

TOP VIEW

1

2

3

–

V

4

S8 PACKAGE

8-LEAD PLASTIC SO

T

= 160°C, θJA = 190°C/WT

JMAX

NC

8

V+

A

7

OUT

6

ADJ

V

5

OS

1792AI
1792I

Consult factory for Military grade parts.

LECTRICAL C CHARA TERIST

E

SYMBOL PARAMETER CONDITIONS (Note 2) MIN TYP MAX MIN TYP MAX UNITS

V

OS

I

OS

I

B

e

n

i

n

R

IN

C

IN

V

CM

CMRR Common Mode Rejection Ratio V
PSRR Power Supply Rejection Ratio VS = ±4.5V to ±20V 88 105 83 98 dB

Input Offset Voltage 0.2 0.6 0.2 0.8 mV

V

S

Input Offset Current Warmed Up (Note 3) 100 400 100 400 pA
Input Bias Current Warmed Up (Note 3) 300 800 300 800 pA
Input Noise Voltage 0.1Hz to 10Hz 2.4 2.4 µV
Input Noise Voltage Density fO = 10Hz 8.3 8.3 nV/√Hz

f

O

Input Noise Current Density fO = 10Hz, fO = 1000Hz (Note 4) 10 10 fA/√Hz
Input Resistance

Differential Mode 10
Common Mode V

Input Capacitance 14 14 pF

Input Voltage Range (Note 5) 13.0 13.5 13.0 13.5 V

CM

V

CM

V

S

CM

ICS

T

= 25°C, VS = ±15V, V

A

= ±5V 0.4 1.0 0.4 1.3 mV

= 1000Hz 4.2 6.0 4.2 6.0 nV/√Hz

= –10V to 8V 10
= 8V to 11V 10

= ±5V 27 27 pF

–10.5 –11.0 –10.5 –11.0 V

= –10V to 13V 85 105 82 100 dB

= 0V, unless otherwise noted. (Note 9)

CM

LT1792AC/LT1792AI

11
11
10

LT1792C/LT1792I

10
10
10

P-P

11
11
10

Ω
Ω
Ω

2

LECTRICAL C CHARA TERIST

E

ICS

T

= 25°C, VS = ±15V, V

A

= 0V, unless otherwise noted.

CM

LT1792

LT1792AC/LT1792AI

SYMBOL PARAMETER CONDITIONS MIN TYP MAX MIN TYP MAX UNITS

A

VOL

V

OUT

SR Slew Rate RL ≥ 2k (Note 7) 2.3 3.4 2.3 3.4 V/µs
GBW Gain-Bandwidth Product fO = 100kHz 4.0 5.6 4.0 5.6 MHz
I

S

Large-Signal Voltage Gain VO = ±12V, RL = 10k 1200 4800 1000 4500 V/mV

V

= ±10V, RL = 1k 600 4000 500 3000 V/mV

O

Output Voltage Swing RL = 10k ±13.0 ±13.2 ±13.0 ±13.2 V

= 1k ±12.0 ±12.3 ±12.0 ±12.3 V

R

L

Supply Current 4.2 5.20 4.2 5.20 mA

= ±5V 4.2 5.15 4.2 5.15 mA

V

S

Offset Voltage R
Adjustment Range

(to VEE) = 10k 10 10 mV

POT

The ● denotes specifications which apply over the temperature range 0°C ≤ TA ≤ 70°C. VS = ±15V, V

LT1792C/LT1792I

= 0V,

CM

unless otherwise noted. (Note 9)

LT1792AC LT1792C

SYMBOL PARAMETER CONDITIONS (Note 2) MIN TYP MAX MIN TYP MAX UNITS

V

OS

∆V

OS

∆Temp
I

OS

I

B

V

CM

CMRR Common Mode Rejection Ratio V
PSRR Power Supply Rejection Ratio VS = ±4.5V to ±20V ● 85 99 81 97 dB
A

VOL

V

OUT

SR Slew Rate RL ≥ 2k (Note 7) ● 2.1 3.1 2.1 3.1 V/µs
GBW Gain-Bandwidth Product fO = 100kHz ● 3.2 4.5 3.2 4.5 MHz
I

S

Input Offset Voltage ● 0.4 0.8 0.8 2.7 mV

= ±5V ● 0.6 1.2 1.2 3.2 mV

V

S

Average Input Offset (Note 6) ● 410 740 µV/°C
Voltage Drift

Input Offset Current ● 180 500 180 500 pA
Input Bias Current ● 500 1800 500 1800 pA

Input Voltage Range ● 12.9 13.4 12.9 13.4 V

= –10V to 12.9V ● 81 104 79 99 dB

CM

Large-Signal Voltage Gain VO = ±12V, RL = 10k ● 900 3600 800 3400 V/mV

V

= ±10V, RL = 1k ● 500 2600 400 2400 V/mV

O

Output Voltage Swing RL = 10k ● ±12.9 ±13.2 ±12.9 ±13.2 V

= 1k ● ±11.9 ±12.15 ±11.9 ±12.15 V

R

L

Supply Current ● 4.2 5.30 4.2 5.30 mA

= ±5V ● 4.2 5.25 4.2 5.25 mA

V

S

● –10.0 –10.8 –10.0 –10.8 V

3

LT1792

LECTRICAL C CHARA TERIST

E

–40°C ≤ TA ≤ 85°C. V

SYMBOL PARAMETER CONDITIONS (Note 2) MIN TYP MAX MIN TYP MAX UNITS

V

OS

∆V

OS

∆Temp
I

OS

I

B

V

CM

CMRR Common Mode Rejection Ratio V
PSRR Power Supply Rejection Ratio VS = ±4.5V to ±20V ● 83 98 79 96 dB
A

VOL

V

OUT

SR Slew Rate RL ≥ 2k ● 2.0 3.0 2.0 3.0 V/µs
GBW Gain-Bandwidth Product fO = 100kHz ● 2.9 4.3 2.9 4.3 MHz
I

S

Input Offset Voltage ● 0.5 1.0 1.2 3.7 mV

Average Input Offset (Note 6) ● 410 740 µV/°C
Voltage Drift

Input Offset Current ● 300 800 300 800 pA
Input Bias Current ● 1200 4000 1200 4000 pA

Input Voltage Range ● 12.6 13.0 12.6 13.0 V

Large-Signal Voltage Gain VO = ±12V, RL = 10k ● 850 3300 750 3000 V/mV

Output Voltage Swing RL = 10k ● ±12.8 ±13.1 ±12.8 ±13.1 V

Supply Current ● 4.2 5.40 4.2 5.40 mA

= ±15V, VCM = 0V, unless otherwise noted. (Notes 8, 9)

S

V

V

R

V

ICS

= ±5V ● 0.8 1.4 1.5 4.2 mV

S

= –10V to 12.6V ● 80 103 78 98 dB

CM

= ±10V, RL = 1k ● 400 2200 300 2000 V/mV

O

= 1k ● ±11.8 ±12.1 ±11.8 ±12.1 V

L

= ±5V ● 4.2 5.35 4.2 5.35 mA

S

The ● denotes specifications which apply over the temperature range

LT1792AC/LT1792AI LT1792C/LT1792I

● –10.0 –10.5 –10.0 –10.5 V

Note 1: Absolute Maximum Ratings are those values beyond which the
life of a device may be impaired.

Note 2: Typical parameters are defined as the 60% yield of parameter
distributions of individual amplifiers.

Note 3: Warmed-up I
temperature of 32°C from 25°C measurements and 32°C characterization
data.

Note 4: Current noise is calculated from the formula:

i

= (2qIB)

n

where q = 1.6 • 10
swamps the contribution of current noise.

Note 5: Input voltage range functionality is assured by testing offset
voltage at the input voltage range limits to a maximum of 2.3mV
(A grade), to 2.8mV (C grade).

and IOS readings are extrapolated to a chip

B

1/2

–19

coulomb. The noise of source resistors up to 200M

Note 6: This parameter is not 100% tested.
Note 7: Slew rate is measured in AV = –1; input signal is ±7.5V, output

measured at ±2.5V.
Note 8: The LT1792AC and LT1792C are guaranteed to meet specified

performance from 0°C to 70°C and are designed, characterized and
expected to meet these extended temperature limits, but are not tested at
–40°C and 85°C. The LT1792I is guaranteed to meet the extended
temperature limits. The LT1792AC and LT1792AI grade are 100%
temperature tested for the specified temperature range.

Note 9: The LT1792 is measured in an automated tester in less than one
second after application of power. Depending on the package used,
power dissipation, heat sinking, and air flow conditions, the fully
warmed-up chip temperature can be 10°C to 50°C higher than the
ambient temperature.

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